const Koa = require('koa')
const app = new Koa()
const views = require('koa-views')
const json = require('koa-json')
const onerror = require('koa-onerror')
const bodyparser = require('koa-bodyparser')
const logger = require('koa-logger')
const cors = require('koa2-cors')

const index = require('./routes/index')
const users = require('./routes/users')

// error handler
onerror(app)

//allow cross domain
app.use(
	cors({
		origin: function (ctx) { //设置允许来自指定域名请求
			// if (ctx.url === '/api') {
			// 	return '*'; // 允许来自所有域名请求
			// }
			// return 'http://localhost:3002'; //只允许http://localhost:3002这个域名的请求
			return '*'
		},
		maxAge: 5, //指定本次预检请求的有效期，单位为秒。
		credentials: true, //是否允许发送Cookie
		allowMethods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'], //设置所允许的HTTP请求方法'
		allowHeaders: ['Content-Type', 'Authorization', 'Accept'], //设置服务器支持的所有头信息字段
		exposeHeaders: ['WWW-Authenticate', 'Server-Authorization'] //设置获取其他自定义字段
	})
);

// middlewares
app.use(bodyparser({
	enableTypes: ['json', 'form', 'text']
}))
app.use(json())
app.use(logger())
app.use(require('koa-static')(__dirname + '/public'))

app.use(views(__dirname + '/views', {
	extension: 'ejs'
}))

// logger
app.use(async (ctx, next) => {
	const start = new Date()
	await next()
	const ms = new Date() - start
	console.log(`${ctx.method} ${ctx.url} - ${ms}ms`)
})

// routes
app.use(index.routes(), index.allowedMethods())
app.use(users.routes(), users.allowedMethods())

// error-handling
app.on('error', (err, ctx) => {
	console.error('server error', err, ctx)
});

module.exports = app